<?php

require_once 'HTMLPurifier/AttrDef.php';
require_once 'HTMLPurifier/CSSDefinition.php';

/**
 * Validates shorthand CSS property background.
 * @warning Does not support url tokens that have internal spaces.
 */
class HTMLPurifier_AttrDef_CSS_Background extends HTMLPurifier_AttrDef
{
	
	/**
	 * Local copy of component validators.
	 * @note See HTMLPurifier_AttrDef_Font::$info for a similar impl.
	 */
	var $info;
	
	function HTMLPurifier_AttrDef_CSS_Background($config) {
		$def = $config->getCSSDefinition();
		$this->info['background-color'] = $def->info['background-color'];
		$this->info['background-image'] = $def->info['background-image'];
		$this->info['background-repeat'] = $def->info['background-repeat'];
		$this->info['background-attachment'] = $def->info['background-attachment'];
		$this->info['background-position'] = $def->info['background-position'];
	}
	
	function validate($string, $config, &$context) {
		
		// regular pre-processing
		$string = $this->parseCDATA($string);
		if ($string === '') return false;
		
		// munge rgb() decl if necessary
		$string = $this->mungeRgb($string);
		
		// assumes URI doesn't have spaces in it
		$bits = explode(' ', strtolower($string)); // bits to process
		
		$caught = array();
		$caught['color']	= false;
		$caught['image']	= false;
		$caught['repeat']   = false;
		$caught['attachment'] = false;
		$caught['position'] = false;
		
		$i = 0; // number of catches
		$none = false;
		
		foreach ($bits as $bit) {
			if ($bit === '') continue;
			foreach ($caught as $key => $status) {
				if ($key != 'position') {
					if ($status !== false) continue;
					$r = $this->info['background-' . $key]->validate($bit, $config, $context);
				} else {
					$r = $bit;
				}
				if ($r === false) continue;
				if ($key == 'position') {
					if ($caught[$key] === false) $caught[$key] = '';
					$caught[$key] .= $r . ' ';
				} else {
					$caught[$key] = $r;
				}
				$i++;
				break;
			}
		}
		
		if (!$i) return false;
		if ($caught['position'] !== false) {
			$caught['position'] = $this->info['background-position']->
				validate($caught['position'], $config, $context);
		}
		
		$ret = array();
		foreach ($caught as $value) {
			if ($value === false) continue;
			$ret[] = $value;
		}
		
		if (empty($ret)) return false;
		return implode(' ', $ret);
		
	}
	
}

